Mechanical coupling



FIG. 1 is a perspective view of our design for a pipe coupling;

FIG. 2 is an end view of the pipe coupling shown in FIG. 6 thereof, the opposite end view being identical thereto;

FIG. 3 is a side view of the pipe coupling thereof, the opposite side view being identical thereto;

FIG. 4 is a top view of the pipe coupling thereof; and,

FIG. 5 is a bottom view of the pipe coupling.

The broken lines shown in FIGS. 1–5 are shown for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a mechanical coupling, as shown and described. 